Patent GB-795441-A (GB)
Title: Improvements in or relating to apparatus for producing hollow cores for foundry purposes
Inventor: TAYLOR GEORGE WILLIAM
IPC: B22C23/00
Filed: 1953-07-20
Abstract: 795,441. Moulding-machines. POLYGRAM CASTING CO., Ltd. May 25, 1954 [July 20, 1953], No. 20132/53. Class 83 (1). [Also in Group XXX] Apparatus for producing hollow-cores for foundry-purposes in which a resin-sand mixture is fed into a heated metal-corebox, excess resin is removed and the coating in the box set by heating, comprises means for aerating and agitating the mixture as it is fed under pressure into the box. At each of two stations 2, 3, core-box-clamps 22, 23 are initially moved into positions of easy access by a piston 28 and linkage 26 controlled by a handle 31. The flanged clamps 22, 23 are operated by screws 24, and can be adjusted to and from each other by screwed-rods 17. When the core-boxes have been clamped in position, they are sprayed with lubricant by a gun 33 and the handles 31 are then actuated to swing the box-halves together along paths determined by fixed rods 12 engaging guide slots 14 on the clamp brackets 13. Heating elements in base-plates 15 are energized and control-knobs 19 are set to give a temperature of about 150‹ C. A hopper 6 is then swung over one core-box and a button 52 on a hand-grip 53 is pressed to admit pressure-air to a line 57. The air passes through and around a perforated cone 62 and through a line 59 to agitate the sand-resin mix above a flow-adjuster 103. After a slight delay a valve operated by the button 52 admits air at a higher pressure to a cylinder controlling the operation of slides (not shown) which allow mixture to pass from the hopper through a mouthpiece 104 into the core-box. A suctionline 110 is connected to the mouthpiece 104 so that no moulding-mixture escapes into the atmosphere. When the core-box is full, the button 52 is released. A button 97 on a hand-grip 96 is then pressed to admit a blast of air through a tube 95, central in the mouthpiece 104, to agitate and blow out excess mixture in the box. The excess is withdrawn through the suction-tube 110 to a dust-extractor which separates the mixture into a bin. Any mixture which does escape is swept through a grille 7 into a bin 109. The coating is left to cure for a few seconds before the lever 31 is moved to separate the clamps, thus leaving the moulding in one half of the box from which it is removed by tapping. Means may be provided to ram the sand in the core-box-cavity. A thermocouple-probe (not shown), connected to an indicator 34 is used for checking the temperature of the box at any stage. In a modification, a lid 112, Fig. 9, on a hopper which is in constant communication with a pressure-air-supply, is opened by a handle on a shaft 139 which, as it turns, actuates a valve to release the air pressure existing in the hopper. The lid is then swung inwardly to secure it by a catch 114 while the hopper is being replenished. When a box is being filled, a shutter 122 is opened by a valve 121 and a collar 129 is slid down over the junction between the mixture exit-pipe 124 and the box to prevent escape of mixture into the atmosphere. Excess mixture is removed by a separate mouthpiece 137, Fig. 10, and ejection-pipe 138. In a further modification, core-box supports are mounted on a table by screw-threaded rods so that they may be rotated to adjust them vertically. Other supports may be adjustable vertically on rods to enable deeper boxes to be accommodated. The boxes are heated before being placed on a table and are removed for curing after they have been filled. Plant. Alternatively, boxes may pass on a conveyer through an oven, beneath a hopper, and then to a position where excess mixture is removed. Excess mixture may also be removed by inverting the core-box. The Provisional Specification describes a machine in which the mixture is agitated by means 23, 25, Figs. 1 and 2 (Prov.), as it passes to a manually-controlled sleeve-valve 29 and a discharge-opening 33. Excess material is removed by a suction-hood 32. At intervals, the mixture supply is cut off and a ram 23 is actuated until the box is full. The filling apparatus is then moved along a track and replaced by a compressed-air and suctiondevice 36, 37 to remove excess mixture. The making of doll's heads by the apparatus is referred to. Specifications 795,442 and 795,443 are referred to.